Cartridge fuse



May 31 1932 J. B. GLowAcKl 1,857,096

CARTRIDGE FUSE Filed Aug. ll. 1927 M ZZ-ig: a l5 Z1 Z1 INEE- l WEM f@ IMm EV MEL Patented May 3, 1932 PATENT OFFICE JOHN B. GLOWACKI, OFCHICAGO, ILLINOIS CARTRIDGE FUSE Application 1aed August 11, 1927.serial No. 212,240.

This invention relates to improved fuses of the cartridge type providedwith a renewable diagonally positioned fuse element and with adjustableclamping or contact members positioned in removable end collars wherebytight contacts may be obtained between the projectiner tips of the fuseelement and the metal thimbles engaged on the ends of a fibre body orsleeve. i It is an object of this invention to provide a cartridge' fusein which a renewable fuse element is adapted to be held in place by endcollars having means adj ustably mounted therein to insure tightcontacts at the vends of the fuse elements.

It is also an object of this invention to provide a cartridge type fusewherein the end caps or closure members are provided with an adjustablehead for insuring proper Contact with the ends of the fuse element andthe thimble ymembers of the cartridge fuse and furthermore permittingfuse elements of different current capacities to be tightly secured inplace.

It is a further object of this invention to provide a cartridge typefuse wherein a Z-shaped fuse element is adapted to be removably mountedin but a single predetermined position.

It is an important object of this invention to provide an improved fuseof the cartridge t pe in which a fibre body portion has metal t iimblemembers rigidly engaged thereon for the purpose of renewably receiving afuse element diagonally disposed Within the casing, with the endsthereof projecting in op posite directions and clamped tightly incontact with the thimble members by means of adjustable apert'ured endcaps.

Other and further important objects of this invention will be apparentfrom the disclosures in the specification and the accompanying drawings.

This invention (in a preferred form) is illustrated in the drawings andhereinafter more fully described.

On the drawings:

Figure 1 is a side elevation of an improved cartridge fuse embodying theprinciplcs of this invention.

f Figure 2 is an end view of the cartridge use.

Figure 3 is a longitudinal vertical section of the cartridge fuse withparts broken away and with parts shown in elevation.

Figure 4 is a longitudinal section of the cartridge fuse taken on lineIV-IV of F igure 3 showing the fuse element in elevation. Figure 5 is anend elevation of the fuse taken on line V-V of Figure 3 with the cap soremoved.

Figure 6 is an end view of the cartridge fuse taken on line VI-VI ofFigure 3 with the cap removed.

Figure 7 is an enlarged detail view of one 65 end of the cartridge fusewith the cap removed and with the fuse element omitted.

Figure 8 is an enlarged transverse detail section of the fuse taken online VIII-VIII of Figure 1.

Figure 9 is a section through one of the end ,caps of the fuse removedfrom the fuse and showing the adjustable head in elevation.

Figure 10 is a plan view of the renewable fuse element removed from thefuse. 76

Figure 11 is a side view of the fuse element.

Figure 12 is a longitudinal section of a modilied type of cartridge fuseshowing the fuse element in elevation. 80

Figure 13 is a section taken through one of the end caps of the modifiedcartridge fuse showing parts in elevation.

As shown on the drawings.

The improved cartridge fuse comprises a 86 cylindrical body or sleeve lconstructed of fibre or other suitable nonconducting material and havingan opening in the middle portion of the wall thereof to receive anindicator designated as a whole by the reference numeral for the purposeof providing a suitable indication when the fuse element has blown. Theindicator 2forms no part of the present invention and is therefore, notdescribed in detail. Both ends of the body 1 are reduced in diameter andexteriorly threaded. Mounted on one end of the body 1 is a metal thimblecomprising an interior-ly threaded sleeve 3 and an extcriorl y threadedsleeve 4 of reduced'diani- 100 eter and connected with the interiorlythreaded sleeve 3 by a shoulder 5. The outer end of the thimble sleeve 4is closed by means of an integral closure plate 6 having a slot providedtherein to one side of the centerof said closure plate to receive oneend 7 of a renewable fuse element. The renewable fuse element consistsof a strip 8 of fusible conducting material having a plurality ofnotches 9 in the longitudinal margins thereof to form a plurality ofspaced narrow connecting necks or links l() each having an opening 11therein. The apertured necks 10 are provided so that the points at whichfusion will taken place are definitely located. The opposite end of thefuse strip 8 is provided with an end piece 12 which normally is slightlybent at a slight angle, as indicated in Flgure 1l, to facilitatemounting of the fuse element in the cartridge sleeve or body 1. The fuseelement is inserted through the opening in the thimble plate 6,permitting the end 7 to lie flat against the outer face of the thimbleplate 6, as indicated in Figures 4 and 5. The fuse strip 8 projectsdiagonally through the bod 1 with the end 12 of the fuse projectingthrough a slot 13 provided to one side of the center of a removablethimble plate 14 against the outer face of which the end or tip. 12 ofthe fuse element is adapted to be bent, thereby Agiving the fuse elementa Z-shape when mounted in position within the cartridge fuse, as clearlyillustrated in Figure 4. The thimble closure plate 14 is provided with apair of oppositely disposed lugs or ears 15 positioned to one side ofthe center of the closure plate 14 and in a line arallel to the slot 13,as shown in Figure The thimble closure plate 14 is adapted to beremovably seated in a recess formed in the outer end of an exteriorlythreaded sleeve 16 which is integrally' joined by means of a shoulder 17to an interiorly threaded thimble sleeve 18 which is threaded on thesecond end of the cartridge fuse body'l. The outer end of the exteriorlythreaded thimble sleeve 16 is provided with a pair of notches at 19 toone side of a center line of said thimble plate to removably receive theears 15 of the thimble closure late 14 in but a single predeterminedposition so that the slot 13 is definitely located with respect to theslot in the closure plate 7 of the o posite thimble and diagonallyopposite tliereto for the urpose of definitely positioning the renewab efuse element 8 in a diagonal predetermined position within' thecartridge fuse body 1.

For the purpose of rigidly holding the thimbles on the opposite endsofthe cartridge fuse body 1 after they have been threaded into positionthereon each of the thimble sleeves 3 and 18, respectively, are providedwith a plurality of inwardly directed pairs of oppositely directedcircumferentially disposed arc shaped indents or gripping teeth 20 whichgrip or bite into the fibre body 1 to rigidly hold the thimbles clampedor locked in position on the body 1 against removal.

Removably threaded on the exteriorly threaded sleeve of each of themetal thimbles is a metal cap comprising an interiorly threaded collar21, the inner end of which is adapted to seat against the shoulder ofthe thimble, leaving the outer end projecting beyond the outer end ofthe respective thimble. The outer end of each of the cap collars 21 isopen and is provided with an inwardly directed stop flange 22 to serveas a stop for limiting the outward movement of a peripherally threadedclosure plate or head 23 which is adjustably mounted within the capcollar 21. Each of the adjustable cap closure heads 23 is provided withan exterior boss 24 having a diametric groove 25 therein to receive ascrew driver or other suitable tool to permit the head 23 to be threadeddownwardly or outwardly within the cap collar 21. Each of the capclosure heads 23 is provided with a central aperture or opening 2G. Aninterior boss 24a is integrally formed on the inner face of each of theadjustable cap heads 23 and is apertured to register with the opening26.l The cap heads 23 are adjustably mounted, as described, to permitsaid heads to be threaded downwardly within their respective collars 21after the collars have been engaged on a fuse thimble tightly seatedagainst the shoulder of said thimble. By applying a screw driver orother suitable tool in the groove 25 of a cap head 23, said head may bescrewed downwardly until the inner boss 24a thereof isbrought intocontact with the bent end of the renewable fuse element to tightly presssaid end of the fuse element into close contact with the end plate ofthe fuse thimble.

The diameter of the inner boss 24a is equal to the width of the fuseelement end member or tip for the purpose of providing a circular spaceor chamber 37 between the end'plate of a thimble and the respective caphead 23, so that any dust or fuse particles resulting from the blowingof a fuse element which might pass through the slots in the thimble endplate will be permitted to settle on the inner face of the adjustablecap heads and, therefore, will not enter and clog the s iral threadpassage between the cap head an the interior of the cap collar.

Itwill thus be noted that the improved Vcartridge fuse provides an easyand convenient means for removing and renewing the fuse element when thesame has blown. The element may be removed by merely unthreading thecaps from the respective thimbles, pulling out the' halves of the blownfuse element, and inserting a new fuse element through the slot in thethimble closure plate 6 while the opposite end 12 of the fuse element isinserted through the slot 13 of the removable thimble closure plate 14after which the fuse element end 12 is bent over, as indicated in Figure6, so that the opposite ends of the fuse element are directed inopposite directions, causing the fuse element to assume a Z-shape withthe main portion of the fuse strip positioned diagonally within thehousing or body 1 `of the cartridgeY fuse. After the new fuse elementhas been placed in position the end caps are threaded onto-theexteriorly threaded sleeves of the thimbles until said cap collars seatagainst the shoulders of the thimbles. A screw driver may now be used tothread the adjustable heads of the caps inwardly with the bosses 24atightly pressing the ends of the fuse elements against the respectiveend plates of the fuse thimbles.

Figures 12 and 13 illustrate a modified type of cartridge fuseparticularly adapted for telephone work and comprising a fibre body orsleeve 27 the ends of which are reduced and exteriorly threaded toreceive thimbles 28 and 29 on the ends thereof. The thimble 28 isprovided with an integral end closure plate 38 provided with an offsetslot for the purpose of receiving one end of a fuse element 30, theother end of which projects through an offset slot in a removableclosure plate 31 provided in the thimble 29 and constructed similar tothe thimble closure plate 14 illustrated in Figure 7. When in positionthe main portion of the fuse element 30 is diagonally positioned in apredetermined position within the body of the fuse body 27 with the endsof the fuse element projecting in opposite directions and disposed tothe outside of the closure plates for the end thimbles. For the purposeof rigidly and tightly holding the bent ends of the fuse element againstthe thimble closure plates an interiorly threaded cap 32 is removablyengaged on the outer exteriorly threaded ends of each of the thimbles 28and 29 to permit a boss 33 integrally formed within the cap to engageagainst an end of the fuse element to tightly press the same against theclosure plate of a fuse thimble. Each of the closure caps 32 is providedwith an outlet passage or opening 34 which continues through anexteriorly threaded shank. or screw 35 having a nut 36 engaged thereon.The outlet apertures or passages in the caps 32 are provided to permitescape of the products resulting from the blowing of the fuse elementwithin the cartridge fuse. The outer ends of the threaded shanks 35 areupset to prevent removal of the nuts 36.

The modified form of cartridge fuse illustrated in Figures 12 and 13affords a convenient arrangement whereby a blown fuse element ma \v bequickly and readily removed from the housing or body 2i' and a new fuseelement inserted in plac thereof by simply unscrewing the end caps,pulling out the halves of the blown fuse element and inserting a newfuse element in the predetermined position made possible by the locationof the offset slots in the closure heads provided in the fuse thimbles.Tight contactsof the ends of the fuse element with the closure plates ofthe thilnbles is assured by the provision of the bosses 33 within theremovable caps 32 firovided on the ends of the cartridge fuse. am awarethat many ychanges may be made, and numerous details yof Constructionmay be varied through a wide range without departing from the principlesof this invention, and I therefore do not purpose limiting the patentgranted hereon, otherwise than necessitated by the prior art. I claim asmy invention:

1. A cartridge fuse comprising a body, a thimble rigidly secured on oneend thereof, a plate integral therewith and having an offset slottherein closed at both ends, an open notched thimble rigidly secured onthe opposite end of said body and countersunk at one end, a removableclosure plate seated in the countersunk end of said thimble and havingan offset slot therein closed at both ends, a pair of oppositelypositioned oifsetprojections formed on said closure plate on they endsof a secant line and adapted to seat inV offset notch-es provided insaid open thimble, a fuse element' removably positioned diagonallywithin said body*l with the ends of said fuse element projecting throughthe slots in said plates and projecting in opposite directions from oneanother, said fuse element having a cross-section sufficient tosubstantially fill up said slots and contact caps removably engaged onsaid thimbles for pressing the respective ends of the fuse element intight contact with said plates to insure positive contacts.

2. A fuse device of the class described comprising a body, a thimblerigidly secured on one end thereof and having a fuse element receivingslot closed at both ends positioned to one side of the center of anintegral closure plate of said thimble, an open countersunk thimblerigidly secured on the opposite end of said body and having a pair ofynotches therein positioned opposite one another to one side of a centerline of said open thimble and on a secant line parallel to said slot, aclosure plate seated in the countersunk end of said open thimble havinga fuse element receiving slot closed at both ends and positioned to oneside of the center thereof, a pair of oppositely positioned lugsintegrally formed on said thimble closure plate to.one side of thecenter line thereof and adapted to seat in the notches of said openthimble to permit the thimble closure plate to be seated in apredetermined position only within the notched end of the open thimble,a fuse element renewably engaged in said body with ZI.

bination with a hollow body, of a closed thimble rigidly secured on oneend thereof and having an offset slot therein with said -slot closed atboth ends, an open thimble rigidly secured on the opposite end of saidbody and having a countersunk seat and a pair of offset notches therein,a closure plate seated in said countersunk seat of said open thimblehaving an o'set slot therein with said slot closed at both ends, and apair of offset lugs integrally formed on said closure plate on a secantline parallel to said slot and adapted to seat in the offset notches ofsaid lopen thimble to receive said closure plate in said` seat in apredetermined position only 'with the slot in said closure' platepositioned diagonally opposite to the slot in the closed thimble.

4. In a fuse device of the class described the combination with a bod ofthimbles threaded on the'ends thereo and a lurality of pairs ofoppositely directed in ents circumferentially cut inwardl from saidthimbles and wedged into sai body to ri idly lock the same againstremoval on said ody.

5. In a fuse device of the class described, the combination with a body,of thimbles threaded on the ends thereof, members cut circumferentiallyfrom said thimbles and arranged in pairs with the members of each pairprojecting toward one another and wedged into said body to afford apositive double locking arrangement between the thimbles and said body,said double locking arrangement being afforded by the threadedengagement between said thimbles and the body and the additional wedgedlocking ar- `angement afforded by said wedged memers.

6. In a fuse device of the class described, the combination with a fiberbody externally threaded at both ends, metal thimbles threaded on theends of said body, a plurality of members struck and cut from saidthimbles and wedged into the threaded portions of said body, saidmembers arranged circumferentially in opposite pairs with the members ofeach pair directed toward one another and spaced closer together thanthe members on the same side of opposite pairs.

7. In a fuse of the class described, the combination with a body, ofthimbles engaged on the ends thereof, and having a plurality of membersstruck and cut circumferentally therefrom with the cut ends of saidmembers wedged into said body, said members arranged with adjacentmembers grouped in pairs and deflected toward one another with the pairsof said members altere Illinois. Y

JOHN B. GLOWACKI.

nately arranged with the members of oneajo

